Buccal drug delivery

ABSTRACT

A lozenge is provided that has stable pH and stable levels of active ingredient over time. It comprises a combination of (i) at least one gum and (ii) at least one non-crystallizing sugar or non-crystallizing sugar alcohol in a matrix designed for controlled buccal delivery of a drug. The lozenge also contains water and optional components selected from flavorings, taste masking agents, colorings, buffer components, pH adjusting agents, excipients, stabilizers and sweeteners. Methods of preparing the lozenge are also provided.

The present invention relates to lozenges for buccal drug delivery andmethods for making lozenges for buccal drug delivery.

A known form of buccal drug delivery uses fast melt technology, which ischaracterised by rapid drug release. A known fast melt product is Zydis,which is formulated as a wafer having a very low density and minimalquantities of excipient. Thus, for example U.S. Pat. No. 5,939,091describes a method of making fast melt tablets comprising SorbitolInstant. Similarly, WO 02/085119 describes a dosage form for intra-oraldelivery of nicotine comprising a hydroxypropylmethylcellulose film.This delivery system is characterised by rapid dissolution providing foralmost instantaneous delivery of the nicotine.

In other forms, the structure of the tablet is modified so as to providea desired delivery profile. Thus, WO 03/039518 describes an oral dosageformulation for delivery of nicotine comprising two layers, the firstproviding for buccal drug delivery and the second providing for deliveryvia the stomach or intestines. This formulation provides an initialrapid release of nicotine in the mouth followed by a slow sustainedrelease of nicotine in the gut.

Also in this category is WO 01/37814 which describes bilayered buccaltablets comprising nicotine. These tablets provide a biphasic release ofnicotine from a modified lactose and magnesium stearate containingtablet.

Some known formulations for administering nicotine contain a gum. Forexample, WO 02/076211 describes an oral dosage formulation comprisingnicotine. A formulation is described which is a hard lozenge having amatrix which is in a glassy, i.e. amorphous physical state. Theselozenges are made and deposited at high temperatures (for example 120°C.) and comprise a sodium carbonate buffer.

Others include EP 0 500 658, which describes a nicotine containingstimulant unit for buccal drug delivery, which can comprise a gumcomponent and, as a sweetener, a sugar component and U.S. Pat. No.6,183,775, which describes a controlled release lozenge comprising asoluble filler, an insoluble film-forming agent, and a swellablepolymer. The lozenges are produced by compression of a dry granulate.

Other known dosage forms include:

-   -   U.S. Pat. No. 3,590,111, which describes the production of        troches by wet and dry granulation procedures. Ingredients        include guar gum, disaccharides and hexahydric saturated        aliphatic alcohols.    -   U.S. Pat. No. 4,829,056, which discloses a buccal tablet        containing etorphine as active ingredient and excipients        including at least one monosaccharide or disaccharide and locust        bean gum.    -   U.S. Pat. No. 5,470,566, which discloses an anticariogenic        chewing gum comprising a gum base, a taste enhancer and urea for        neutralizing dental plaque.    -   GB 2 049 417, which discloses an antacid composition compressed        into lozenges which can comprises mannitol and xanthan gum.    -   U.S. Pat. No. 5,156,845 describes a dry mouth lozenge comprising        a non-cariogenic sweetener such as sorbitol, a gum base and a        fluoride, and    -   WO 96/00070, which discloses a nicotine-containing composition        that additionally contains caffeine. Examples of dosage forms        include lozenges which contain sugars and adhesive substances        including gums.

The known delivery systems tend to produce a rapid release of drug inthe mouth or do not provide a controlled rate of release. A furtherdisadvantage of known delivery systems for administering nicotine, isthat nicotine may be lost in manufacture or storage due tovolatilisation or chemical instability.

Another disadvantage of known hard lozenges containing sodium carbonateis that the sodium carbonate buffer may decompose at the temperaturesrequired for manufacture. Such lozenges may also be subject to variableor over-rapid drug release as they have a mouth feel which is likely toprompt chewing or sucking rather than parking the lozenge and allowingit to dissolve.

Thus there is a need for an improved drug delivery system which isstable and provides controlled buccal delivery of a drug.

According to a first aspect of the present invention, there is provideda glassy lozenge for buccal drug delivery comprising:

-   -   a) a matrix;    -   b) an active agent;    -   c) water; and    -   d) optionally one or more components selected from flavourings,        taste masking agents, colourings; buffer components, pH        adjusting agents, excipients, stabilizers and sweeteners,    -   wherein the matrix comprises (i) at least one gum and (ii) at        least one non-crystallising sugar or non-crystallising sugar        alcohol.

It is particularly preferred for the matrix of lozenges according to theinvention to comprise:

-   -   (i) at least one gum, and    -   (ii) at least one sugar and/or at least one sugar alcohol,        characterised in that a major proportion of component (ii)        consists of:        -   A. at least one non-crystallising sugar,        -   B. at least one non-crystallising sugar alcohol, or        -   C. a mixture of at least one non-crystallising sugar and at            least one non-crystallising sugar alcohol.

Preferably such lozenges are characterised in that 50-0.90 wt %, morepreferably 55-85 wt %, and most preferably 60-80 wt % of component (ii)consists of:

-   -   A. at least one non-crystallising sugar,    -   B. at least one non-crystallising sugar alcohol, or    -   C. a mixture of at least one non-crystallising sugar and at        least one non-crystallising sugar alcohol.

Preferably components A, B and C are incorporated into the compositionin a pre-existing non-crystallising form.

According to an alternative definition of lozenges according to theinvention, it is particularly preferred for the matrix of lozengesaccording to the invention to comprise:

-   -   (i) at least one gum, and    -   (ii-a) at least one sugar and/or at least one sugar alcohol,        characterised in that a major proportion of component (ii-a)        consists of a non-crystallising mixture of sugars and/or sugar        alcohols.

In producing lozenges according to this alternative definition it is notessential that components A, B and C are incorporated into thecomposition in a pre-existing non-crystallising form.

In other words, the sugar and/or the sugar alcohol in component (ii-a)may initially be in crystalline form. The lozenges of the invention mayaccordingly be produced by forming a mixture comprising at least onecrystallizing sugar and/or at least one crystallizing sugar alcohol,whereby the act of forming the mixture (or subsequent treatment stepsperformed thereon, such as heating or evaporation of water) results inthe mixture as a whole being non-crystallising. Thus in one embodiment,a mixture is formed of (A) non-crystallising sorbitol and (B) acrystalline grade of xylitol, the mixture as a whole beingnon-crystallising.

As the non-crystallizing sugars and/or sugar alcohols are sweet, it isnot necessary for additional sweetening agents (such as sucrose) to beused. In fact, it has surprisingly been found that the advantageouspharmacological properties of the lozenge according to the invention aremost pronounced if the lozenges are substantially sucrose-free. By“substantially sucrose-free” is meant that the lozenges containing lessthan 10 wt % sucrose, preferably less than 5 wt % and most preferablyless than 2% sucrose. It is particularly desirable for the lozenges tocontain less than 1 wt % sucrose.

Typical glassy lozenges according to the invention comprise thefollowing matrix components in the relative parts by weight specified(excluding water):

Acacia gum 55-62 Sorbitol 27-34 Xylitol  7-11 Alkaline metal (e.g. Na) 1-13 phosphate(s)especially:

Acacia gum 56-58 Sorbitol 29-31 Xylitol  8-10 Alkaline metal (e.g. Na)1.5-2.0 phosphate(s)

Typical water contents of the lozenges are 5-20 wt. %, especially 10-15wt. %.

Lozenges of the invention have been found to exhibit improved pHstability and stability of the active agent over time and to provide acontrolled drug release profile.

According to an embodiment of the invention the lozenge provides forcontrolled release of the active agent. According to this embodiment,the lozenge dissolves or disintegrates gradually, thus releasing acontrolled dose of the drug for absorption across the buccal mucosa.This controlled drug release avoids delivery of an initial burst ofdrug, and, in some cases, allows the patient to titrate the amount ofdrug received. Thus, for example, the patient can remove the lozengefrom their mouth once the symptoms for which the active agent isadministered have been reduced to a tolerable level or eliminated.

The release profile of the active agent or the dissolution profile ofthe lozenge is governed by the matrix composition and lozenge size andcan be varied according to the nature of the active agent and thedesired effect. Thus, the dissolution profile can be altered, whilstretaining the same amount of the active agent, by varying the lozengesize and/or the proportion of gum in the lozenge. A smaller overalllozenge size will result in faster dissolution. Similarly a reduced gumcontent will result in faster lozenge dissolution.

A suitable dissolution profile for lozenges of the invention is suchthat after 20 minutes approximately 35-65% of the lozenge has dissolved,after 40 minutes, approximately 60-90% of the lozenge has dissolved, andafter 60 minutes more than 70% of the lozenge has dissolved. Preferredlozenge sizes are in the region of 300 mg-2 g. Typically lozenges arenot smaller than 300-400 mg and are not larger than approximately 1.5 g,approximately 1.75 g or approximately 2 g. In general, lozenge size (interms of dimensions and shape) should be suitable for parking thelozenge in the buccal cavity.

The ratio of matrix components can be varied to vary the dissolutionprofile. Typically, the matrix comprises from 40-90% of the gumcomponent and from 60-10% of the non-crystallising sugar ornon-crystallising sugar alcohol component. In further embodiments of theinvention the matrix comprises 50-80% or preferably 55-75% of the gumcomponent and 20-50% or preferably 25-45% of the non-crystallising sugaror non-crystallising sugar alcohol component.

To calculate the percentage contribution of each component, it must beappreciated that the end lozenge would generally have a moisture contentof approximately 5-20% by weight, typically approximately 10-15%. Gumarabic, when used, has a water content of typically about 10%. Thisshould be taken into account unless the proportions of ingredients aredefined in terms of the anhydrous equivalent.

Any suitable gum may be used in the lozenges of the invention. Suitablegums include gum acacia, gum arabic, carob gum, carrageenan, ghattiigum, guar gum, karaya gum, pectin, tragacanth gum, locust bean gum andxanthan gum. A preferred gum component is gum acacia, especiallysupplied in spray dried form for manufacture of lozenges.

In addition to the gum, the matrix also comprises one or morenon-crystallising sugars and/or one or more non-crystallising sugaralcohols. Non-crystallising forms of sugars or sugar alcohols arecommercially available and may conveniently be used. Alternatively,sugars or sugar alcohols can be heat treated to providenon-crystallising properties. For example, sugars or sugar alcohols maybe heated to approximately 110-120° C., preferably 113-117° C., forexample, about 114° C. until converted to a non-crystallizing form.Suitable sugars and sugar alcohols for use according to the inventioninclude non-crystallising or treated forms of dextrose, maltose,sucrose, fructose, glucose syrup, invert sugar syrup, honey, laevulose,sorbitol, xylitol, maltitol, mannitol and isomalt. Preferrednon-crystallising sugars or non-crystallising sugar alcohols includenon-crystallising forms (or mixtures) of sorbitol, xylitol, maltitol,mannitol, and isomalt. According to a particular embodiment of theinvention the non-crystallising sugar or non-crystallising sugar alcoholis a non-crystallising form of sorbitol or a mixture ofnon-crystallising sorbitol with a minor amount, up to 45%, of xylitol.The xylitol is preferably incorporated into the sorbitol/xylitol mixturein non-crystallising form. However, it has been found that if acrystalline grade of xylitol is admixed with non-crystallising sorbitol,a resulting non-crystallising mixture may be obtained. Thus, generally,it is preferred for each lozenge component to be provided in anon-crystallizable form before blending with other components. Howeverif more than one sugar or sugar alcohol is used, the non-crystallizingnature of component (iii) in its totality may derive from the fact thata mixture is used, irrespective of the fact that one of the plurality ofsugars/sugar alcohols was initially provided in crystalline form.

The non-crystalline nature of the matrix yields a glassy, amorphouslozenge which is generally translucent and flexible. Lozenges preparedin specific embodiments of the invention, described in more detail inthe examples, demonstrated long-term active agent stability. The potencyand/or integrity of the active agent in lozenges of the invention hasbeen found to be substantially constant after storage periods of, forexample, three, six, nine twelve or eighteen months.

The glassy, non-crystalline nature of the matrix results in asignificant reduction in hydrolysis of the active agent and may resultin no hydrolysis. Although not being bound by theory, it is believedthat the structure of the matrix (e.g. a hydrogel) results in therebeing less water and fewer free ions (particularly hydroxyl ions) toinitiate hydrolysis. Moreover, the active agent is bound in the matrixand little of none is lost via evaporation from the lozenge. Incontrast, the active agent is more susceptible to hydrolysis and is moresusceptible to evaporation in a crystalline matrix, such as those ofknown non-gel lozenges. Thus, the lozenges of the invention exhibitimproved stability in storage.

The non-crystalline nature of the matrix may also contribute to the longterm stability of the water content of lozenges of the invention.Lozenges of the invention have been found to have a substantiallyunchanged water content after storage for, for example, three, six, ninetwelve or eighteen months.

It is believed that the non-crystallising sugars or non-crystallisingsugar alcohols, particularly when used in the preferred proportionsdescribed herein, contribute to the glassy structure of the lozenges ofthe invention. Thus, the non-crystallising sugars or non-crystallisingsugar alcohols are structural components of the lozenges, not merelysweeteners, and contribute to the improved stability of the lozenges.

The lozenges according to the invention will normally contain water.Thus according to an embodiment of the invention, the lozenges have afinal water content of approximately 5-20% by weight. Lozenges accordingto the invention may comprise, for example, approximately 9-15% byweight water, preferably approximately 10-13% by weight water.

Lozenges according to the invention may further comprise a buffer systemcomprising buffer components. For example, the buffer system maycomprise one or more alkaline metal salts and corresponding weak acidsor weak bases. Any suitable physiologically compatible buffer system maybe used which provides buffering capacity at the desired lozenge pH. Forexample, phosphate, citrate, and carbonate buffers may be included, butthe preferred buffer for use according to the invention is a phosphatebuffer system. The phosphate buffer system may comprise, for example,sodium dihydrogen phosphate and tri-sodium phosphate and details offurther phosphate buffers are set out in the examples. Most preferablycitrate buffer and carbonate buffers are excluded and the sole bufferingagents are phosphate salts.

It is preferred that the buffer system in the lozenge provides, in themouth, a pH suitable for buccal absorption of the active agent. Thebuffer can vary according to the active agent, and generally varies soas to provide a pH at which the active agent is in an un-ionized form.For nicotine-containing lozenges, the pH is preferably in the range7.5-9.0, more preferably 8.0-8.4. The lozenge may also contain a pHadjusting agent suitable for bringing the pH into the desired range.Such pH adjusting agents are generally basic pH adjusting agents, e.g.water soluble alkali salts, though any suitable agent may be used.Examples of suitable pH adjusting agents include sodium hydroxide,potassium hydroxide and the like.

The presence of a buffer in lozenges of the invention (particularlyphosphate buffering agents) results in improved long-term stability inthe pH value of the lozenges. For example, lozenge pH values may besubstantially stable during storage for up to three months, six months,nine months, twelve months, or eighteen months. Use of a phosphatebuffer system has been found to be particularly effective in providinglong-term stability, in lozenge pH.

Also, the presence of a buffer, particularly a phosphate buffer, hasbeen found to contribute to the long-term stability of the active agentduring storage. This may be, in part, due to the maintenance of a stablepH. The active agent in lozenges of the invention may be stable for upto three months, up to six months, up to nine months, up to twelvemonths, or up to eighteen months. While not being bound by theory, it isbelieved that a synergistic effect between the preferred phosphatebuffer and other components (especially non-crystallizable sorbitol)contributes to the advantages described.

In addition, it may be desirable to have the active agent present in thelozenge in a particular form, such as an un-ionised form. The lozenge pHcan be set to a particular value or range of values suitable for a givenactive agent by varying the nature or amount of the buffering agentsand/or pH adjusting agents.

It is believed that control of the lozenge pH, and in particular the useof phosphate buffers is advantageous in providing an improved taste or“mouth feel”. The use of phosphate buffers, for example, avoids thepresence of the “soapy” taste or texture sometimes associated with otherbuffers (e.g. carbonates). This may be useful in encouraging reluctantpatients to take necessary medication.

Carbonate buffers are not preferred as they tend to decompose at hightemperatures, causing bubbles to form in the matrix. Citrate buffers arenot preferred for basic buffered lozenges, for example lozenges havingnicotine as the active agent, as they do not provide the optimal pH.

Lozenges according to the invention may optionally comprise flavourings,vitamins, anti-oxidants, anti-fungals, anti-bacterials, taste maskingagents, colourings, excipients, stabilisers and sweeteners. Suitablecomponents may be selected from those known in the art. Flavourings caninclude toffee flavouring QL17192, lemon oil, orange oil, and spearmintflavour 79020. Colourings may include any colouring approved for food orpharmaceutical use. Excipients may include talc, maize starch, and Capol4348F. According to some embodiments of the invention, the excipientsform a coating on the surface of the lozenge and are not incorporatedinto the lozenge itself. Sweeteners may include artificial sweetenerssuch as aspartame and sodium saccharin, sugars and sugar alcohols aspreviously listed. It is preferred that sugars or sugar alcohols used assweeteners be non-crystallising or be treated to impartnon-crystallising properties and that sucrose is absent.

According to another aspect of the invention, a lozenge for buccal drugdelivery is provided comprising a matrix and a phosphate buffer, whereinthe matrix comprises (i) a gum, and (ii) a sugar or sugar alcohol.

In lozenges of this aspect of the invention, the phosphate bufferpreferably comprises a pH adjusting agent and one or more phosphatebuffer salts. Generally, the buffer and its components are as describedfor other lozenges of the invention. Further, the remaining componentsof the lozenge of this aspect are as described in relation to otherlozenges of the invention, apart from the matrix. The sugar component ofthe matrix is not necessarily non-crystallizing, and hence this aspectof the invention relates to use of a phosphate-based buffer system inpreparation of a matrix for a buccal lozenge. Use of phosphate-basedbuffers has been found to confer taste and stability advantages asdemonstrated in the examples provided herein.

Generally, and in relation to all lozenges of the invention, the activeagent can be selected from any active agent, drug, pharmaceutical or thelike that is desired to be delivered buccally, that is to say absorbedacross the buccal mucosa.

Drugs particularly suitable for delivery using lozenges of the inventioninclude alkaloids, for example nicotine, alkaloidal drugs, anti-emetics(for example 5-HT antagonists), agents for migraine treatment (forexample 5-HT agonists), analgesics (for example cannabis, Δ9-THC andalkaloids), drugs that benefit from rapid uptake, drugs used in acutetherapy, drugs that need to be or are preferentially taken lying down,drugs taken by patients who cannot or do not wish to swallow or drugs tobe taken where it is undesirable to use a large amount of water. Drugsare preferably readily absorbable across the buccal mucosa. Drugsparticularly suitable for delivery via lozenges of the invention aredrugs for which the first pass effect is not beneficial, ie drugs ofwhich the potency is reduced as a result of metabolism in the liver.Mucosal delivery is ideal for such drugs as they are directly absorbedinto the bloodstream without first passing through the liver.

Particularly preferred drugs for delivery using lozenges of theinvention include nicotine, the analgesic Δ9-THC, the anti-emeticondansetron (a 5-HT₃ antagonist), and the anti-migraine drug sumatriptan(a 5-HT₁ agonist). Drugs for delivery using lozenges of the inventionmay optionally be in the form of a pharmaceutically acceptable salt.

For lozenges in which the active agent is nicotine, this may be providedas synthetic nicotine or nicotine extracts from tobacco plants, i.e. thegenus Nicotiana. The nicotine can be in the form of the free base,pharmaceutically acceptable acid addition salts or oxidation productssuch as nicotine-1′-N-oxide. Lozenges according to the invention mayalso comprise alkaloids with the same direction of activity as nicotineincluding nor-nicotine and lobeline (e.g. of the species Lobeliaceae andLobelia), methylanabasine and anabasine.

The drug delivery system of the invention may be used to administer anysuitable dose of an active agent. Typical doses may be in the range0.5-10 mg, but doses of approximately up to 200 mg can be delivered bylozenges of the invention. Typically different doses of a given drug areprovided by lozenges having the same size, but with varying drugconcentration.

The delivery system provided by the lozenges of the invention isparticularly suitable for active agents where it is desirable to limitpatient exposure to the agent. The controlled release characteristics ofthe lozenges allow self-titration of the drug dosage by the patient.This is useful, for example, when the lozenges are used to deliveragents for migraine treatment or analgesics. Once sufficient activeagent has been absorbed to overcome the symptoms for which the agent hasbeen administered, the remainder of the lozenge can be removed from thepatient's mouth.

According to a second aspect, the invention provides a method of makinga lozenge for buccal drug delivery comprising a matrix, an active agentand water comprising the steps:

-   -   (a) mixing a gum, at least one non-crystallising sugar or sugar        alcohol and water;    -   (b) adding an active agent and mixing;    -   (c) moulding the mixture to form lozenges.

The method of the invention preferably includes at least one heatingstep (d), normally carried out between steps (a) and (b) and a finalconditioning step to reduce the water content of the lozenges.

According to a further aspect, the invention provides a method of makinga lozenge comprising a matrix, an active agent and water for buccal drugdelivery comprising the steps:

-   -   a) mixing a gum, one or more non-crystallising sugars or        non-crystallising sugar alcohols and water;    -   b) heating the mixture with mixing;    -   c) adding an active agent and mixing; and    -   d) moulding the mixture to form lozenges.

The method includes a step of heating and mixing the combination of thegum and sugar component in water, ensuring a thoroughly mixed,homogenous mass is obtained. Known methods do not heat and mix thesecomponents together and can result in lozenges that have an inconsistentcomposition across the lozenge, leading to an inconsistent texture orappearance. Lozenges prepared according to the method of the inventionhave a consistent composition and demonstrate improved appearance andimproved stability during storage.

Preferably the mixture is heated in step (b) to at least 90° C.,generally approximately 110-120° C., more preferably 113-117° C. Thisensures that the components are fully dissolved, ensures the matrixcomponents are in a non-crystallising form, and facilitates preparationof a homogeneous mass.

The methods and components of the invention advantageously allowpreparation of the cooked mass and incorporation of the activeingredient at relatively low temperatures. Known methods of preparingsugar-containing lozenges and/or confectionary typically employtemperatures well in excess of 100° C. and often in excess of 130° C. Wehave found that we can avoid these high temperatures but still generatea matrix having consistent properties and yielding a lozenge which isstable in storage. Methods of the invention employ sufficient water toensure that the gum and sugar components are fully dissolved at thetemperatures used, and the amount of water used in the methods can behigher than used in prior art methods. In consequence, the methods ofthe invention generally include a step of drying the lozenges after theyhave been moulded, and the methods generally do not include a step ofcarrying out mixing and/or heating at such a temperature or under suchconditions that water is substantially removed from the mass prior tomoulding. Further, once the matrix is prepared the active agent is addedto the mass at temperatures sufficiently low to avoid degradation of theactive agent due to heat or loss due to volatilisation. Addition of theactive agent preferably takes place at a temperature of 100° C. orlower, more preferably of 90° C. or lower and in particular at 80° C. orlower. Subsequent processing steps, such as the moulding step, also takeplace preferably at 100° C. or lower, more preferably 90° C. or lowerand in particular 80° C. or lower. A consequent advantage is that activeagent loss or degradation is minimised during preparation of lozengesand during and after moulding. Thus, methods according to the inventionprovide lozenges having improved uniformity of active agent contentbetween lozenges.

The active agent to be added to the cooked mass may be formulated invarious ways, according to the nature of the active agent. For example,the active agent may be added in the form of a micronised powder, anethanolic solution, or an aqueous solution.

Optionally, the method further comprises the steps of adding one or morebuffering agents and adding a pH adjustment agent to adjust the pH toapproximately 7.5-9.0. The mixture can be allowed to rest followingaddition of all components but prior to moulding to allow air to escapefrom the mass. Use of lower temperatures during processing steps leadsto reduced degradation of lozenge components, for example reduceddegradation of carbonate-containing components to release carbon dioxidewhich would form bubbles in the mixture. Both result in improved lozengecomposition and appearance.

Typically moulding step (d) above comprises the substeps of (d1)transferring the mixture to a moulding apparatus and (d2) moulding themixture to form lozenges. After moulding a further step comprisingdrying the lozenges can be carried out.

Thus, specific lozenges according to the invention can be made, forexample, by combining a 70% solution of non-crystallising sorbitol,xylitol and gum acacia, dissolving in water and heating to a temperatureof approximately 113-117° C., for example 114° C. Heating may beachieved by direct heat transfer, for example, using a jet heater or byindirect heating using a heat exchange surface. Heating to thistemperature endows the xylitol with non-crystalline characteristics.

Following heating, the pipework is chased with additional water,buffering agents and optional flavourings are added to the cooked massand the pH of the mass is adjusted, for example, with sodium hydroxide.

For nicotine-containing lozenges, the pH of the mass is preferablyapproximately 0.5-1.5 pH units below the final pH of the lozenge.Preferred pH values for the cooked mass lie in the range of pH 6.9-7.1,and preferred final pH values for the lozenge, after addition ofnicotine, are in the range 8.0-8.5. Nicotine is added to the cooked massdissolved in 70% alcohol or in aqueous solution. Preferably a 10%solution of nicotine in 70% alcohol is used. The mixture is stirred forpreferably at least 10 minutes and then allowed to rest forapproximately 30 minutes to allow air to escape from the mass beforeforming. During the resting period the mass is preferably maintained atapproximately 70° C.

It is preferred that after nicotine is added to the mass, moulding ofthe lozenges is not overly delayed. Maintaining the mass at the restingtemperature for extended periods of time can result in loss of potencydue to volatilisation of nicotine, which has a low vapour pressure.

Lozenges may be moulded using known technology. In such methods mass maybe transferred to a hot funnel located above depositing funnels. Themass may then be deposited through nozzles into trays of preformedstarch moulds. Preferably the starch moulds are conditioned by runningthrough the moulding process several times, for example 7-8 times or 10times. This conditioning provides repeated compression and heating toremove water, and results in enhanced shape retention by the starchmoulds. After the mass has been deposited in the moulds, the moulds arestacked and transferred to drying ovens. The lozenges may be dried atany suitable temperature, for example 63-67° C., for approximately 30-34hours. Preferably the final moisture content of the lozenges isapproximately 10%.

Thus, a lozenge having a weight of approximately 2.25 g may have a finalweight of approximately 1.50 g. Following drying, lozenges are boltedfrom the starch moulds, and starch is removed from the surface of thelozenges using air jets or brushes. The lozenges may then be coated witha glazing or anti-sticking agent such as Capol. This glazing provides ashiny or waxy finish to the lozenges, prevents sticking, and removes anyresidual starch attached to the lozenge surface.

The method of manufacture of the present lozenges is distinct fromprocesses commonly used in manufacture of tablets, which are formed bycompressing dry or granulated components.

According to a further aspect, the invention provides use of (i) a gumcomponent and (ii) a non-crystallising sugar or non-crystallising sugaralcohol component in manufacture of a matrix for a buccal lozenge. Thematrix is preferably glassy and non-crystalline in character. Anysuitable gum component and non-crystallising sugar or non-crystallisingsugar alcohol component can be used, for example, the componentsembodiment. The components can be used to manufacture a matrix byfollowing steps (a) and (b) of the method of the second embodiment.

Generally, preferred lozenges of the invention containing water, gumacacia, non-crystallizing sorbitol, non-crystallising xylitol,non-crystallising maltitol, non-crystallising isomalt or othernon-crystallizing sugar alcohol derivatives, homologues or associatedsugars, and optional components such as phosphate buffers sodium orpotassium hydroxide, and flavourings fall within the formula:—

Excipient or Active Ingredient Lozenge Drug Substance 0.01-200 mg AcaciaSpray Dried (anhydrous equivalent) 600-1000 mg Sorbitol, sugar alcohol,derivative or homologue 200-500 mg Non-crystallising Xylitol 100-200 mgPhosphate salt (1) 0-50 mg Phosphate salt (2) 0-50 mg pH adjuster Todesired pH Water, Purified 9-15% of total mass Flavouring 0-10 mg Total1000-2000

The invention is now illustrated in the following non-limiting examples.

EXAMPLES Example 1 Manufacture of Lozenges General Procedures andEquipment

Equipment

The following equipment items were used:

Dispensing scoops, sampling scoops, buckets and covers; batch mixingcontainer; syrup pump; mass pump; jet cooker; holding tank; mixing tank;starch moulding machine; starch moulding trays; drying chamber; producttrays and covers; polishing drum.

Initial Sampling

Sample 250 mL of purified water from the reservoir in the dispensingarea. Send to laboratory for testing of E. coli and total viable aerobiccount. Record the conductivity.

Preparation of Buffer Solution

In a tared bucket, dispense 30 kg of water, purified at 70° C. Add thebuffers and dissolve and stir. Retain for the addition of buffer step.

Prepare a 30% Sodium hydroxide solution: In a tared bucket, dispense 14kg of water, purified and carefully add the sodium hydroxide withconstant stirring. When all the sodium hydroxide has dissolved, stir andretain for addition in later step.

Preparation of Nicotine Solutions

Prepare approximately 70% ethanol solution by mixing 14 liters ofethanol 96% with 6 liters of item water, purified.

For 1 mg—10% Nicotine Solution: Dispense the nicotine into a taredbucket. Add 5 kg of 70% ethanol solution mix and cover. Retain foraddition in later step.

For 2 mg—10% Nicotine Solution: Dispense the nicotine into a taredbucket. Add 10 kg of 70% ethanol solution mix and cover. Retain foraddition in later step.

For 4 mg—10% Nicotine Solution: Dispense the nicotine into a taredbucket. Add 20 kg of 70% ethanol solution mix and cover. Retain foraddition in later step.

Preparation of Uncooked Mass

Dispense 276 kg of water, purified into the batch mixing container. Heatto 70° C. and thermostatically maintain the temperature. Add thesorbitol liquid (non-crystallizing), acacia (spray dried) and xylitol.Heat the pre-mix slurry with stirring for between 30 and 40 minutesmaintaining a temperature of between 68° C. and 72° C.

Pump the mass to the holding tank. Run the pump until the batch mixingcontainer is empty and complete the transfer with water.

Raise the temperature of the mass to between 70° C. and 74° C. and startthe Jet Cooker. Pump the mass from the holding tank through the Jetcooker into the mixing tank, maintaining a temperature of between 113°C. and 117° C. and a vacuum of between −0.4 and −0.8 BAR. Continue thecooking process until all the mass has passed through the Jet Cookerinto mixing container. Complete the transfer with water. Draw the lastof the mass through the cooker into mixing tank by force of the vacuum.Maintain a cooking temperature of 113°-117° C.

Flavouring

For Classic Flavour—Allow the cooked mass to stand without stirring forapproximately 20 minutes. Start the stirrer on slow speed and add 2.2 kgof Toffee Flavour QL17192.

For Citrus Flavour—Allow the cooked mass to stand without stirring forapproximately 20 minutes. Start the stirrer on slow speed and add 2.1 kgof Orange Oil BP and 0.5 kg of Lemon Oil Ph. Eur.

For Spearmint Flavour—Allow the cooked mass to stand without stirringfor approximately 20 minutes. Start the stirrer on slow speed and add2.0 kg of Spearmint flavour.

Addition of Buffer and Nicotine

While continuing to stir add the buffer solution prepared in earlierstep. Add 8.5 kg of 30% sodium hydroxide solution and if necessary, makefurther additions of 30% sodium hydroxide solution until a pH of 6.7 to7.1 is obtained. While continuing to mix the mass, add the 10% nicotinesolution completing the transfer with 1 liter of water, purified. Adjustthe final batch weight to 1190.0 kg using water, purified. Close thetank and mix for 5 minutes. Maintain the temperature at between 68° C.and 70° C.

Moulding and Processing

(Note: Moulding may be performed concurrently with batch formulationwhen using pre-conditioned starch.)

Preparation of moulding machine and moulds: Select the appropriate mouldand dust with talc. Attach to the moulding machine. If using newmoulding starch, fill mogul hopper with starch and operate the machineon recycle, filling and emptying the trays until 10 cycles have beencompleted. Add 25 kg of starch to the hopper after each cycle. If usingpre-used (conditioned) moulding starch, fill the mogul hopper andpresent the pre-filled trays to the mogul for emptying, re-filling andstacking.

Allow the mass to rest for 20 minutes.

Set the moulding funnel temperature at 70° C. Pump the formulated massfrom mixing tank into the moulding funnel of the mogul machine. Afterthe transfer has been completed allow the formulated mass initiallytransferred to rest for 20 minutes. Start the moulding machine anddeposit through the 48 mouthpieces into the starch moulds, adjusting themoulding weight to 2.25 g. The mogul tank is automatically kept at aconstant fill level until the entire formulated product has beentransferred from the mixing tank.

Operate the moulding machine at a rate of between 6 and 11 trays perminute until all the formulated mass has been deposited. Once mouldingis complete, transfer the stacked trays to the drying chamber. Dry thelozenges at between 63° C. and 67° C. for between 30 and 34 hours.Record the temperature, time and drying atmosphere (% RH). Turn off theheating in the drying chamber and allow the lozenges to cool for 24hours. The air temperature should drop to 30° C. before continuing.Return the trays to moulding machine. Bolt and sieve the lozenges fromthe starch collecting the lozenges in labelled product trays. Once full,cover the labelled trays with tray covers.

Finishing

Sample for chemical and microbiological testing. Transfer the lozengesto the sorting line, and remove any damaged or misshapen lozenges.Transfer the sorted lozenges to the polishing drum and apply Capol 4348F at a rate of approximately 1 g per kilo of lozenges. (only about twothirds of the applied Capol 4348 F is deposited on the lozenges). Duringpolishing sample every 30 minutes, bulking the samples. This sample isretained for use in Quality Control release testing. Record the weightand time for each sample taken. Pack the lozenges in labelled doublewrapped polyethylene bags. Record the weight of each bag and dispatchthe bulk packed lozenges to Inpac for packaging.

Packaging

Check the bulk container to confirm the identity of its contents.Assemble the lozenges, and pack seal and label them. During thepackaging process “finished packed samples” are taken at regularintervals and a check lozenge-count is made.

Notes

If new moulding starch is used, complete the moulding prior tocommencing batch formulation. To ensure the quality of the recycledstarch, the total viable count test is performed prior to each mouldingrun.

Materials for Lozenges

Nicotine (Base) Ph Eur—Siegfried CMS, Zofingen Switzerland

Talc Powder Ph Eur—mfs

Toffee Flavouring QL17192—Quest International PO Box 2 1400 CA BussumHolland

Tri-sodium Phosphate dodecahydrate extra pure E339—Merck KGaA, 64271Darmstadt Germany

Xylitol CX Ph Eur—Danisco Sweeteners, Redhill Surrey, UK

C*Sorbidex NC 16205/7 (Sorbitol Non-crystallising Ph Eur)—CerestarKrefeld Germany

Instantgum AS—(Gum Acacia Ph Eur)—Colloides Natuerels International,Rouen, France

Meritena 100—(Maize Starch to Ph Eur), Amylum Group, Vaexjoe, Sweden

Capol 4348F—Kaul GMBH, Elmsholm Germany (polishing antisticking agent)

Ethanol 96% Ph Eur—Kemethyl, Haninge Sweden.

Sodium Dihydrogen Phosphate Dihydrate Ph Eur—Merck KGaA Darmstadt,Germany

Sodium Hydroxide Ph Eur—Merck KGaA Darmstadt, Germany

Lemon Oil Ph Eur

Orange Oil BP—R.C. Treat and Co Ltd, Suffolk UK

Spearmint Flavour 79020—Givaudan, Dortmund Germany

Example 2

Lozenges were prepared using the method of Example 1, having thefollowing constitution:—

Classic Flavour

Formulation (kg) Grade 1 mg 2 mg 4 mg Active Ingredient Nicotine Ph.Eur. 0.53 1.06 2.12 Excipients Acacia, Spray-Dried Ph. Eur. 475 475 475Sorbitol, Liquid Ph. Eur. 253 253 253 (Non Crystallizing) Xylitol Ph.Eur. 75.9 75.9 75.9 Sodium Dihydrogen Phosphate Ph. Eur. 16.0 16.0 16.0Dihydrate Tri-sodium Phosphate In-House 7.2 7.2 7.2 Dodecahydrate SodiumHydroxide Ph. Eur. 5.7 5.7 5.7 Water, Purified Ph. Eur. 354.5 353.9352.9 Ethanol (96 Per Cent)* Ph. Eur. 3.5 7 14 Toffee flavour QL17192In-House 2.2 2.2 2.2 Total weight 1190 1190 1190 (for 530,000 lozenges)*= Evaporates during manufacturing processExcipients not Included in Lozenge Formulation:—

Formulation (kg) Excipients Grade 1 mg 2 mg 4 mg Talc** Ph. Eur. 0.1 0.10.1 Maize Starch** Ph. Eur. 0.7 0.7 0.7 Capol 4348 F** In-House 0.5 0.50.5 **= On surface only, not incorporated into lozenge

Example 3

Lozenges were prepared using the method of Example 1, having thefollowing constitution:—

Citrus Flavour

Formulation (kg) Grade 1 mg 2 mg 4 mg Active Ingredient Nicotine Ph.Eur. 0.53 1.06 2.12 Excipients Acacia, Spray-Dried Ph. Eur. 475 475 475Sorbitol, Liquid Ph. Eur. 253 253 253 (Non Crystallising) Xylitol Ph.Eur. 75.9 75.9 75.9 Sodium Dihydrogen Phosphate Ph. Eur. 16.0 16.0 16.0Dihydrate Tri-sodium Phosphate In-House 7.2 7.2 7.2 Dodecahydrate SodiumHydroxide Ph. Eur. 5.7 5.7 5.7 Water, Purified Ph. Eur. 354.6 354.0353.0 Ethanol (96 Per Cent)* Ph. Eur. 3.5 7.0 14 Orange Oil BP 2.1 2.12.1 Lemon Oil Ph. Eur. 0.5 0.5 0.5 Total weight 1190 1190 1190 (for530,000 lozenges) *= Evaporates during manufacturing processExcipients not Included in Lozenge Formulation

Formulation (kg) Excipients Grade 1 mg 2 mg 4 mg Talc** Ph. Eur. 0.1 0.10.1 Maize Starch** Ph. Eur. 0.7 0.7 0.7 Capol 4348 F** In-House 0.5 0.50.5 **= On surface only, not incorporated into lozenge

Example 4

Lozenges were prepared using the method of Example 1, having thefollowing constitution:—

Spearmint Flavour

Formulation (kg) Active Ingredient Grade 1 mg 2 mg 4 mg Nicotine Ph.Eur. 0.53 1.06 2.12 Excipients Acacia, Spray-Dried Ph. Eur. 475 475 475Sorbitol, Liquid Ph. Eur. 253 253 253 (Non Crystallising) Xylitol Ph.Eur. 75.9 75.9 75.9 Sodium Dihydrogen Ph. Eur. 16.0 16.0 16.0 PhosphateDihydrate Tri-sodium Phosphate In-House 7.2 7.2 7.2 Dodecahydrate SodiumHydroxide Ph. Eur. 5.7 5.7 5.7 Water, Purified Ph. Eur. 354.7 354.1353.1 Ethanol (96 PerCent)* Ph. Eur. 3.5 7.0 14 Spearmint flavourNycomed In-House 2.0 2.0 2.0 1043417 Total weight (for 530,000 1190 11901190 lozenges) *= Evaporates during manufacturing processExcipients not Included in Lozenge Formulation

Formulation (kg) Excipients Grade 1 mg 2 mg 4 mg Talc** Ph. Eur. 0.1 0.10.1 Maize Starch** Ph. Eur. 0.7 0.7 0.7 Capol 4348 F** In-House 0.5 0.50.5 **= On surface only, not incorporated into lozenge

Example 5

Lozenges were prepared using the method of Example 1, substitutingmaltitol for sorbitol in lozenge B, having the following constitution:—

Toffee Flavour

Excipient or Active Ingredient Lozenge A Lozenge B Nicotine (mg)   2.0  2.0 Acacia Spray Dried  815.5+  800.5+ (anhydrous equivalent) Sorbitolor Maltitol Liquid 334.9 (sorbitol) 328.9 (maltitol) (anhydrousEquivalent) Xylitol  143.5  139.8 Sodium dihydrogen  23.3  23.5phosphate (anhydrous equivalent) Tri-sodium phosphate   5.9   6.0(anhydrous equivalent) Sodium Hydroxide  10.8  11.0 Water, Purified QS~1500 QS ~1500 Ethanol 96%   0   0 Toffee Flavour QL17192   4.2   4.1Total 1500 1500 +based on 9.2% water content used in pilot batchmanufacture All salts are given as anhydrous equivalents due to additionof water and drying of deposited lozenges.

Example 6 Measurement of pH in Lozenge

Measurement of pH of the lozenges made according to the invention, andalso for comparison with known lozenges was undertaken by testing pH ofa solution prepared by dissolving 1 g of finely divided lozenge in 20 mLof deionised water.

Example 7 Dissolution of Lozenges

Lozenges were prepared with the aim of providing a dissolution profileof, at 20 minutes=Mean of 35%-65%, at 40 minutes=Mean of 60%-90% and at60 minutes=Mean greater than 70% and with the aim of providing stabilityof this profile over long term storage.

A first batch of lozenges were tested at 0 and 12 months aftermanufacture with the following results (the figures indicate percentdissolution):—

TABLE 1 Individual Data Mean 20 40 60 20 40 60 mins mins mins mins minsmins Mean 45.1 73.3 83.7  0M Mean 45.1 73.3 83.7 Min 34.6 50.2 72.8 Min39.0 67.3 77.4 Max 64.9 91.6 91.6 Max 60.1 87.4 88.9 Mean 42.2 72.1 87.312M Mean 42.2 72.1 87.3 Min 34.4 60.0 77.7 Min 37.4 62.4 81.8 Max 54.484.1 97.9 Max 50.8 79.9 96.7

A second test was carried out on nicotine containing toffee flavouredlozenges, with the following results:—

TABLE 2 Batch Strength 0 minutes 20 minutes 40 minutes 60 minutes 1A 2mg 0 40 73 89 1B 2 mg 0 44 75 88 3A 4 mg 0 43 68 80 3B 4 mg 0 43 73 80

Dissolution was measured in pH 6.8 mixed phosphate buffer (5.76 g/LiterDisodium hydrogen orthophosphate, 2.29 g/liter Potassium dihydrogenorthophosphate, 1000 mL) using the Basket Method (Ph. Eur., 2.9.3,“Dissolution test for solid dosage forms”) at 100 rpm.

Example 8 Lozenge Properties

Lozenges according to the invention were tested for stability andcompared with lozenges of the invention of different formula and withknown lozenges.

Stability of Active Ingredient

The long term stability of the active ingredient of the lozenge wastested, and the data are presented in Table 3. These demonstrate theenhanced stability characteristics of the lozenge. The introduction of aphosphate buffer system has been shown to complement chemical stabilityof the alkaloid nicotine. This is contrary to the incompatibilitydetailed in the literature, e.g. in the Handbook of PharmaceuticalExcipients. (Arthur H. Kibbe, Ph. D Pharmaceutical Press 2000)

TABLE 3 Long Term Assay Stability of Alkaloid (nicotine) containingLozenges with Phosphate Buffer stored at 25° C./60% RH. 0 3 6 9 12 18Batch Strength months months months months months months 5A 1 mg 96 102101 95 97 — 5B 1 mg 95 102 99 104 98 — 1A 2 mg 103 98 99 97 98 100 1B 2mg 103 99 101 97 97 100 3A 4 mg 98 95 98 95 97 97 3B 4 mg 98 96 96 95 9596Comparative Data

The stability of 2 known nicotine-containing products were tested, andthe data set out below.

TABLE 4 25° C./60% RH Batch Number 0 months 3 months 6 months NiquitinCQ 031757 98.7% 95.2% 96.3% Lozenge 2 mg Niquitin CQ 032871 95.7% 95.8%97.5% Lozenge 2 mg Niquitin CQ 032166 103.6% 96.9% 96.9% Lozenge 4 mgNicorette Gum 2 mg 072546A 97.1% 104.0% 103.1%

TABLE 5 40° C./75% RH Batch Number 0 months 3 months 6 months NiquitinCQ 031757 98.7% 95.2% 93.9% Lozenge 2 mg Niquitin CQ 032871 95.7% 95.8%97.5% Lozenge 2 mg Niquitin CQ 032166 103.6% 95.3% 95.2% Lozenge 4 mgNicorette Gum 2 mg 072546A 97.1% 93.8% 100.3%ph Stability

The pHs of aqueous solutions (5%) prepared from the lozenges buffered byphosphate salts were measured and it was found that these demonstrateexcellent pH stability over extended periods of time. The resultsobtained are represented in Tables 6a and 6b. The data show betterstability than for citrate buffering system presented in Tables 7a and7b.

The phosphate buffers used were one or a combination of two or more ofSodium dihydrogen phosphate, di-sodium hydrogen phosphate, potassiumdihydrogen phosphate, di-potassium hydrogen phosphate, sodium hydroxide,potassium hydroxide, tri sodium phosphate and other alkali earth metalphosphate salts and hydrated salts thereof.

TABLE 6A pH stability of Alkaloid (nicotine) containing Lozenges withPhosphate Buffer stored at 25° C./60% RH. 0 3 6 9 12 18 Batch Strengthmonths months months months months months 5A 1 mg 8.1 8.0 8.2 8.0 8.3 —5B 1 mg 8.2 8.1 8.2 8.1 8.5 — 1A 2 mg 8.0 8.2 8.0 8.0 8.0 8.2 1B 2 mg8.4 8.5 8.0 8.5 8.5 8.3 3A 4 mg 8.3 8.2 8.0 8.1 8.4 8.1 3B 4 mg 8.4 8.48.4 8.3 8.5 8.4

TABLE 6b pH stability of Alkaloid (nicotine) containing Lozenges withCitrate Buffer stored at 25° C./60% RH. Batch Strength 0 months 2 months3 months LF6 2 mg 7.1 6.9 6.7

TABLE 7a pH stability of Alkaloid (nicotine) containing Lozenges withPhosphate Buffer stored at 40° C./75% RH. 0 1 2 3 6 Batch Strengthmonths months months months months 5A 1 mg 8.1 8.0 8.1 8.0 8.0 5B 1 mg8.2 8.2 7.9 8.0 8.1 1A 2 mg 8.0 8.2 8.3 8.2 8.0 1B 2 mg 8.4 8.6 8.3 8.58.2 3A 4 mg 8.3 8.4 8.2 8.2 8.0 3B 4 mg 8.4 8.5 8.3 8.4 8.2

TABLE 7b pH stability of Alkaloid (nicotine) containing Lozenges withCitrate Buffer stored at 40° C./75% RH Batch Strength 0 months 1 month 2months 3 months LF6 2 mg 7.1 6.7 6.5 6.2Water Content

The moisture content of lozenges was evaluated during stability studiesand the data obtained for moisture content for the phosphate bufferedalkaloid (nicotine) lozenges and citrate buffered alkaloid lozenges arepresented in Tables 8a and 8b.

Lozenges were prepared with the aim of a moisture content between 9 and15% of total lozenge weight as determined by loss on drying after 24hours at 105° C., this content to be stable during storage.

TABLE 8a Water Content of Alkaloid (nicotine) containing Lozenges withPhosphate Buffer stored at 25° C./60% RH. 0 3 6 9 12 18 Batch Strengthmonths months months months months months 5A 1 mg 10.5% 11.4% 10.0% 9.5% 12.2% — 5B 1 mg 12.7% 12.5% 10.8%  9.9% 12.9% — 1A 2 mg 11.5%10.1% 10.0% 11.6% 11.8% 10.7% 1B 2 mg 11.3% 13.9%  9.9% 13.4% 14.2%10.5% 3A 4 mg 11.3% 11.6% 10.4% 11.7% 12.1% 10.6% 3B 4 mg 10.8% 10.9%10.0% 11.4% 11.3% 10.8%

TABLE 8b Water Content of Alkaloid (nicotine) containing LozengesManufactured with Citrate Buffer stored at 25° C./60% RH. 1 3 6 9 12Batch Strength 0 months months months months months Prov 2 mg 9.4% 10.6%10.4% 9.8% 15.0% 15.9% 2 Prov 2 mg 12.9% 13.7% 12.8% 12.2% 16.0% 16.1% 4Prov 4 mg 13.0% 14.1% 12.2% 12.5% 14.9% 15.9% 6 Prov 4 mg 14.7% 14.6%11.7% 14.5% 14.0% 15.9% 8

Examples 9-14

Lozenges were prepared using a modified method of Example 1, in whichthe active agent was added to the formulation either as a micronisedpowder, or an ethanolic or aqueous solution. In Examples 9-11, in whichthe drug was ondansetron, the drug was added as a powder or an ethanolicsolution. For Examples 12-14, in which the drug was sumatriptansuccinate, the drug was added as a powder or an aqueous solution.

The lozenges were made with and without buffers to achieve physiologicalor stability-enhancing pH values for the matrix.

Example 9

Lozenges were prepared as described above, having the followingconstitution:—

Ondansetron 4 mg/8 mg (as hydrochloride) Gum Acacia 250 mg-400 mgXylitol 50-200 mg Sorbitol 80-250 mg Water 40-80 mg Flavour 5-15 mgColour 3-5 mg With or without Bitterness Reducing agent (0.1-20 mg)

Example 10

Lozenges were prepared as described above, having the followingconstitution:—

Ondansetron 4 mg/8 mg (as hydrochloride) Gum Acacia 250 mg-400 mgXylitol 50-200 mg Isomalt 80-250 mg Water 40-80 mg Flavour 5-15 mgColour 3-5 mg With or without Bitterness Reducing agent (0.1-20 mg)

Example 11

Lozenges were prepared as described above, having the followingconstitution:—

Ondansetron 4 mg/8 mg (as hydrochloride) Gum Acacia 250 mg-400 mgXylitol 50-200 mg Maltitol 80-250 mg Water 40-80 mg Flavour 5-15 mgColour 3-5 mg With or without Bitterness Reducing agent (0.1-20 mg)

Example 12

Lozenges were prepared as described above, having the followingconstitution:—

Sumatriptan 50 mg/100 mg (as succinate) Gum Acacia 300 mg-500 mg Xylitol100-200 mg Sorbitol 100-300 mg Water 50-100 mg Flavour 5-15 mg Colour3-5 mg With or without Bitterness Reducing agent (0.1-20 mg)

Example 13

Lozenges were prepared as described above, having the followingconstitution:—

Sumatriptan 50 mg/100 mg (as succinate) Gum Acacia 300 mg-500 mg Xylitol100-200 mg Isomalt 100-300 mg Water 50-100 mg Flavour 5-15 mg Colour 3-5mg With or without Bitterness Reducing agent (0.1-20 mg)

Example 14

Lozenges were prepared as described above, having the followingconstitution:—

Sumatriptan 50 mg/100 mg (as succinate) Gum Acacia 300 mg-500 mg Xylitol100-200 mg Maltitol 100-300 mg Water 50-100 mg Flavour 5-15 mg Colour3-5 mg With or without Bitterness Reducing agent (0.1-20 mg)

The invention accordingly provides lozenges, and methods of manufacturethereof, for controlled buccal release and delivery of drugs.

The invention claimed is:
 1. A method of making a glassy lozengecomprising a non-crystalline matrix having a hydrogel structure, anactive agent and water for buccal drug delivery comprising the steps: a)mixing a gum, one or more non-crystallising sugars or non-crystallisingsugar alcohols and water; b) heating the mixture with mixing; c) addingan active agent and mixing; and d) moulding the mixture to formlozenges; wherein the matrix comprises (i) at least one gum and (ii) atleast one non-crystallising sugar or non-crystallising sugar alcohol;wherein the matrix comprises, by weight, from 40-90% of gum component(i), and from 60-10% of the non-crystallising sugar or non-crystallisingsugar alcohol component (ii); wherein the lozenge dissolves ordisintegrates gradually; wherein the active agent is selected from ananti-emetic agent, an agent for migraine treatment, and an analgesicagent; and wherein step (b) comprises heating the mixture to at least90° C.
 2. A method according to claim 1, wherein the mixture is heatedto approximately 110-120° C.
 3. A method according to claim 1 comprisingthe further steps: b1) adding one or more buffering agents; and b2)adding a pH adjustment agent to adjust the pH to approximately 7.5-9.0.4. A method according to claim 1, comprising the further step ofallowing the mixture to rest.
 5. A method according to claim 1, whereinstep d) comprises the substeps of: d1) transferring the mixture to amoulding apparatus; and d2) moulding the mixture to form lozenges.
 6. Amethod according to claim 1 further comprising the step of drying thelozenges.
 7. A method according to claim 1 wherein the active agent isadded in the form of a micronised powder, an ethanolic solution or anaqueous solution.
 8. A method of making a glassy lozenge for buccaldelivery comprising a non-crystalline matrix having a hydro gelstructure, an active agent and water comprising the steps of: (a) mixinga gum, one or more non-crystallising sugars or non-crystallising sugaralcohols, (b) adding an active agent selected from an anti-emetic agent,an agent for migraine treatment, and an analgesic agent and mixing, and(c) moulding the mixture to form lozenges; wherein the matrix comprises(i) at least one gum and (ii) at least one non-crystallising sugar ornon-crystallising sugar alcohol; wherein the matrix comprises, byweight, from 40-90% of gum component (i), and from 60-10% of thenon-crystallising sugar or non-crystallising sugar alcohol component(ii); and wherein the lozenge dissolves or disintegrates gradually.